Wednesday, August 12, 2009
Pest Control with NO Chemicals- The Namchic Story
Namchic is a young little garden nestled up in the Arunachal foothills in Changlang district, close to the Burma (Myanmar) border. Planting started in the year 2000 & the area has steadily grown to 120 hectares of a mix of high quality tea plants. Most of the garden comprises of the following clones - S3A3, P-126A, TV-1,TA-17, N-436 & T3E3.
As can be expected in gardens with a major area covered in high quality clones, the pests have been quite a nightmare. Helopeltis, Red Spider mites and Green fly have been the major cause of the garden spending almost Rs.7000/ ha in an effort to control these pests in 2008. The incidence of pests & cost of control has steadily increased each year. The situation in Dec ‘08 & Jan ’09 was worse, thanks to the worst drought since this plantation began.
The list of chemicals being used & the volumes of them was frightening. But then many other ‘well-organised’ gardens are even more frightening. They had asked for help in mid 2008 in controlling pests but I declined then; I told them that my suggestions would be so dramatically different from the ‘tredmill-of-chemical-controll’ they were on, that they would reject them outright. However, during the process of training the staff and executives on other aspects like plucking, pruning, young tea management, etc. the executives would keep wanting to know more and more about pest control specially because their problems continued to get worse. In the late evening training secessions this would keep coming up & as I saw interest build up, I slowly started whetting their appetite : -
a) “ The laws of nature demand that we look at the whole system . To control any individual organism, we need to understand how it relates to the ecosystem in which it operates.”-John Teasdale –a scientist with USDA Agricultural Research Services
b) “ We must change our philosophy, abandon our attitude of human superiority and admit that in many cases in natural environments we find ways and means of limiting populations of organism in a more economical way than we can do it ourselves.” - Canadian entomologist, G.C. Ullyett in 1950 s.
c) Talking about the ideal conditions in an estate when there is a delicate balance in the whole estate & its surroundings - when pests increase the predators have more food & so their population increases, and pests reduce. When the pests reduce the predator’s food reduces & so their population comes down.
d) This delicate balance is what sustained agriculture for centuries till we started wanting to dominate nature. Then came the chemicals and things have never been the same.
e) I started identifying beneficial insects in Namchic & showing in the field how some of them were being killed by the chemicals being sprayed.
Finally by January 2009 their interest had built up enough and they were really keen on this change. They were ready & so I became the change agent. From that day the chemicals were removed from the garden ( I asked each assistant to keep a can of their favourite chemical in the store, as they might feel more comfortable with them at hand. But these were not to be used without my prior permission. They were not touched). The rest of the 30 + chemicals were sent off to a partner’s garden.
I then started on the Whole Ecosystem approach to pest control and 6 months on I am amazed with the sterling work the whole team has done. It is actually far far better than I could have wished for –
· the pests are under good control
· the garden is looking very healthy
· the costs are down
· the ‘poisons’ are out of the system
· the crop is 46.13% up till end of July
I did not expect such wonderful results in such a short time. But they are there to see. Some of the major negatives have actually become positives – e.g. the jungle all around the garden is normally held responsible for the sheltering of helopeltis and looper; we have found them being used as safe havens by our many beneficials. They have actually helped build up the beneficials population very fast. The whole management team needs a commendation.
What all has changed and happened at the estate –
· We generally concentrate on the tea plant and especially the leaf we harvest. But to manage a tea plantation well, it is important to understand that the tea plant is only one of the many parts of the tea ecosystem. This ecosystem is composed of many parts, including the tea plant, shade trees, other plants, the soil, insects and diseases that feed on the plants, insects and animals that feed on the pests, the weather, the pruning & plucking policy and many other parts. Every part has a function & each part affects the other parts, helping to maintain balance and stability.
· A comprehensive approach to nurturing populations of beneficials has been adopted
§ rearing fields, conservation buffers and other methods to attract build the beneficial organisms that protect our crops.
§ Beneficial predatory and parasitic organisms generally do not flourish in fields with only one plant species. They need ‘overwintering’ sites & different types of microenvironments – where they can find protection from their own natural enemies. These have been created by letting natural vegetation grow along waterways, bare patches, roadsides …. In future no big plots of the same clone will be planted in one area
· There is a tremendous increase in ladybird beetles, praying mantis of different types, predatory wasps, spiders, dragonflies, birds….
· Pests generally succeed by adapting to the specific food, water, shelter & light conditions in a particular farming system. They explode only when external factors upset this delicate balance. By the stopping of chemicals we have partly ensured least upsetting of an important external factor.
· We are not neglecting the golden opportunity to prevent, even while we seek to cure.
· With chemicals removed we have introduced some biocides etc – neem, karanj (Pongamia pinnata) & beauveria bassiana. But the whole idea is to slowly ease these out too, as the balance in the environment gets established. We have also started on some of our own concoctions prepared from plants & waste.
· Even for nutrition we have started making some concoctions from waste and these have recently been introduced in some young teas, to slowly ease out fertilizers.
· The obsession with having the garden weed-free is out the window. We tolerate a bit of weeds as long as they don’t compete too much with the tea plants. And we try and encourage the softer weeds to takeover from the noxious ones.
· Last month we were observing a looper caterpillar walking along a citronella leaf and suddenly we saw it being attacked by a spider which swallowed its head & would not let it go. (they gave me time to take a few photographs – these are shown below).
· The population of cobwebs has grown. We saw a helopeltis caught in one of them. So with the population of webs growing a lot of the adults are going to keep becoming the spiders prey. We also saw another spider pounce upon a wasp & eat it (see photograph).
Lots of things nature is taking over, we just need to keep aiding nature.
We are trying to use the four basic principles of IPM:
1. Grow a healthy plant. Strong, vigorous plants are better able to tolerate insect damage. Pests can never be completely eradicated, so don't try! Instead, manage them at a tolerable level that balances costs and benefits (including economic & environmental) and also provides food for the predators.
2. Protecting and helping natural enemies. Many natural enemies live naturally within the tea field. Others live in wild plants in nearby fields. Just like the crop and pest insects are managed, natural enemies also must be managed so that they become abundant and effective.
3. Regular field surveillance, observation and analysis. The planter team must have good and latest information to make decisions. Pests, natural enemies, the growth stage of the crop, and weather are among the factors that should be observed and analyzed. If there is a presence of or build-up of beneficials, then do not go in for biocides.
4. The management in the field needs to become the experts. They must have confidence in their own knowledge and their ability to make their own decisions.
Would this be the best or easiest way to go organic?
Fertilizers - - 42.65%
Herbicides - - 19.98%
Pesticides - - 34.35%
Mandays - - 13.07%
Plucker’s Productivity - + 8.52%
Crop + 149262 - + 46.13%
The Mature Tea Yield is going to cross 3000Kgs/ha at current trends.
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